Moscow: Russian Sports Minister Vitaly Mutko said on Saturday that 27 of the country's athletes have tested positive for meldonium since the endurance-boosting drug was banned on 1 January, 2016.

"Twenty-seven have tested positive for meldonium and there are some 127 cases in the world," Mutko told R-Sport news agency. "But these figures can change."

Meldonium was propelled into the headlines earlier this month after Russian tennis star Maria Sharapova announced she had tested positive for the drug at the Australian Open in January.

Tablets and vials of meldonium, also known as mildronate. AP

Since then, a string of high-profile Russian athletes, including Olympic swimmer Yulia Efimova, admitted the drug had been detected in their systems.

The World Anti-Doping Agency (WADA) said Thursday it had recorded 123 meldonium cases since the ban came into force.

The identities of all of the athletes who have tested positive for the drug have not been disclosed.

Russia's scandal-ridden athletics federation -- suspended in November after a WADA independent commission found evidence of state-sponsored doping in Russian track and field -- announced four meldonium cases among its athletes earlier this week.

Moscow has pledged to undertake sweeping reforms to revamp its anti-doping programme in time for its track and field stars to compete at the Rio de Janeiro Olympics in August.

Russian sports authorities are now scrambling to clean house before a council meeting of the International Association of Athletics Federations (IAAF) in May, which will likely decide whether Russian athletes will be allowed to compete in Rio.